Related Rule
United Kingdom of Great Britain and Northern Ireland
Practice Relating to Rule 60. Improper Use of the United Nations Emblem or Uniform
The UK LOAC Manual (2004) states: “It is prohibited to … make use of the distinctive emblem of the United Nations, except as authorized by that Organization.” 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 5.10.
Under the UK ICC Act (2001), it is a punishable offence to commit a war crime as defined in Article 8(2)(b)(vii) of the 1998 ICC Statute. 
United Kingdom, ICC Act, 2001, Sections 50(1) and 51(1) (England and Wales) and Section 58(1) (Northern Ireland).
A training video on IHL produced by the UK Ministry of Defence illustrates the rule that the false use of emblems is forbidden. 
United Kingdom, Ministry of Defence, Training Video: The Geneva Conventions, 1986, Report on UK Practice, 1997, Chapter 2.4.